<template>
    <el-breadcrumb
        class="app-breadcrumb"
        separator="/"
    >
        <transition-group name="breadcrumb">
            <el-breadcrumb-item
                v-for="(item, index) in breadcrumbs"
                :key="item.path"
            >
        <span
            v-if="item.redirect === 'noredirect' || index === breadcrumbs.length-1"
            class="no-redirect"
        >{{ $t('route.' + item.meta.title) }}</span>
                <a
                    v-else
                    @click.prevent="handleLink(item)"
                >{{ $t('route.' + item.meta.title) }}</a>
            </el-breadcrumb-item>
        </transition-group>
    </el-breadcrumb>
</template>

<script lang="ts">
    import * as pathToRegexp from 'path-to-regexp'
    import { Component, Vue, Watch } from 'vue-property-decorator'
    import { RouteRecord, Route } from 'vue-router'

    @Component({
        name: 'Breadcrumb'
    })
    export default class extends Vue {
        private breadcrumbs: RouteRecord[] = []

        @Watch('$route')
        private onRouteChange(route: Route) {
            // if you go to the redirect page, do not update the breadcrumbs
            if (route.path.startsWith('/redirect/')) {
                return
            }
            this.getBreadcrumb()
        }

        created() {
            this.getBreadcrumb()
        }

        private getBreadcrumb() {
            let matched = this.$route.matched.filter((item) => item.meta && item.meta.title)
            const first = matched[0]
            if (!this.isDashboard(first)) {
                matched = [{ path: '/dashboard', meta: { title: 'dashboard' } } as RouteRecord].concat(matched)
            }
            this.breadcrumbs = matched.filter((item) => {
                return item.meta && item.meta.title && item.meta.breadcrumb !== false
            })
        }

        private isDashboard(route: RouteRecord) {
            const name = route && route.name
            if (!name) {
                return false
            }
            return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
        }

        private pathCompile(path: string) {
            // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
            const { params } = this.$route
            console.log(pathToRegexp)
            const toPath = pathToRegexp.compile(path)
            return toPath(params)
        }

        private handleLink(item: any) {
            const { redirect, path } = item
            if (redirect) {
                this.$router.push(redirect)
                return
            }
            this.$router.push(this.pathCompile(path))
        }
    }
</script>

<style lang="scss" scoped>
    .el-breadcrumb__inner,
    .el-breadcrumb__inner a {
        font-weight: 400 !important;
    }

    .app-breadcrumb.el-breadcrumb {
        display: inline-block;
        font-size: 14px;
        line-height: 50px;
        margin-left: 8px;

        .no-redirect {
            color: #97a8be;
            cursor: text;
        }
    }
</style>
